Question

What do receptors trigger?

Answer 1

Receptors trigger signal transduction pathways and cellular responses when a hormone or ligand binds to them. This interaction sets off a cascade of events that can alter gene expression or change the cell's activity. Different receptors enable cells to respond to a wide range of stimuli, amplifying and transmitting the initial signal through a network of cellular pathways.

Step-by-step explanation:

Receptors are specialized proteins that can trigger a cascade of biochemical reactions within a cell in response to binding with their corresponding signaling molecules or ligands. When a hormone binds to hormone receptors, it often initiates a biophysical signal that can lead to further signal transduction pathways, or it can directly influence the activation or inhibition of genes within the cell. These receptors may change shape to bind to other cellular components, such as G-proteins on the cytoplasmic surface of the plasma membrane, which then undergoes a process where GTP displaces GDP, activating downstream effects like the production of cAMP and the activation of PKA. This sequence of events amplifies the signal inside the cell, leading to various responses including changes in gene expression or cellular activity.

Additionally, cells contain a variety of receptors, enabling them to respond to diverse stimuli. Some receptors can bind multiple different ligands and elicit a response to physical changes in the environment, chemical diffusion across membranes, or even detect electromagnetic radiation in the case of human vision or other unique sensory abilities in animals. A signaling pathway or cascade is initiated once these receptor-ligand interactions occur, involving second messengers and a series of enzyme and protein activations that eventually result in a change in the cell's function or behavior.

Answer 2

Cells have proteins called receptors that bind to signaling molecules and initiate a physiological response. Different receptors are specific for different molecules. Dopamine receptors bind dopamine, insulin receptors bind insulin, nerve growth factor receptors bind nerve growth factor, and so on. In fact, there are hundreds of receptor types found in cells, and varying cell types have different populations of receptors. Receptors can also respond directly to light or pressure, which makes cells sensitive to events in the atmosphere.